Conventionally, as disclosed in PTLs 1 and 2, a method of applying a phosphorescent coating composition to the surface of an iron, nonferrous metal, alloy steel, or other metal substrate has been disclosed. For example, PTL 1 discloses a method in which the surface of a metallic plate is coated with a phosphorescent coating composition, and a transparent coating layer is formed on the phosphorescent coating composition layer and printed layer so that the film of the phosphorescent coating composition on the surface is not damaged by pressing or the like. Further, PTL 2 discloses a method in which a porous black chemical conversion film is formed by electrolysis on the surface of a metal substrate, and a primer coat film and a phosphorescent coating composition are applied to the surface of the film formed, and further the resultant surface is coated with a transparent topcoat film. The phosphorescent coating is coated by these coating methods so that the phosphorescent coating is durable when used for a long term and is prevented from being peeled off.